The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
The cooling circuit of an internal combustion engine and more particularly coolant flow in the cooling circuit of an internal combustion engine in a motor vehicle is critical not only from the fundamental standpoint of dissipating the heat of combustion to the ambient but also to accurately control the temperature of the engine to optimize performance and fuel economy.
Significant engineering and design effort is directed to these operational parameters, especially the latter given increasingly stringent fuel economy requirements. Unfortunately, even the most sophisticated cooling system configurations are subject to variations caused by, for example, manufacturing and assembly variables and wear and aging of the components such as the pump impeller, the radiator and the hoses. These variations cause variations in system backpressure which can result in flow reduction and temperature variations that deviate from design goals.
With older engines having engine driven coolant pumps (and less stringent performance expectations and requirements) such backpressure variations were of little moment. Today, an increasing number of internal combustion engines, obviously subject to today's performance expectations and requirements, utilize electrically driven coolant pumps, which, unfortunately, are highly sensitive to backpressure variations. A engine cooling system utilizing an electric pump that initially met all heat dissipation and temperature control requirements, as components wear and age and system backpressure changes, may no longer achieve the desired design goals. Because coolant flow and thus temperature and heat dissipation affect cylinder wall and cylinder head temperature, an engine operating at other than design or optimal temperature will compromise fuel economy.
The present invention addresses this problem.